CN102405424B - Sheet and light-emitting device - Google Patents

Abstract

Disclosed is a transparent sheet used in a manner that one surface thereof adjoins a light-emitting body. The other surface of the sheet is so divided into multiple micro-regions (d) that the diameter of the largest one of the circles inscribing in the micro-regions lies in the range from 0.2 [mu]m to 1.5 [mu]m. Any of the micro-regions (d) adjoins two or more other micro-regions(delta) and is surrounded by the two or more other micro-regions(delta). The micro-regions (delta) comprises micro-regions (delta b) randomly selected from the micro-regions (delta) in a proportion of 40% to 98% and the other micro-regions (delta a). First micro-bodies having a thickness d and an effective refractive index na are arranged in the micro-regions (delta a), and second micro-bodies having the thickness d and an effective refractive index nb higher than the effective refractive index na are arranged in the micro-regions (delta b).

Description

Thin slice and light-emitting device

Technical field

The present invention relates to a kind of by making face and the transparent thin slice that luminophor adjacency is used and the light-emitting device that uses this thin slice of one side.

Background technology

Fig. 1 has represented to use the cross-section structure of light-emitting device and the propagation state of light of common organic electroluminescent device (organic EL).On substrate 101, stacked above one another has electrode 102, luminescent layer 103, transparency electrode 104, and on transparency electrode 104, mounting has transparency carrier 105.By apply voltage between electrode 102, transparency electrode 104, point S by the inside of luminescent layer 103 is luminous, and this light is direct or seeing through transparency electrode 104 after electrode 102 reflections, and at lip-deep some P of transparency carrier 105 with respect to surperficial face normal with angle θ incident, and after this point reflects, shine air layer 106 sides.

If the refractive index of transparency carrier 105 is n ' ₁, incidence angle θ is than critical angle θ _c=sin ^-1(1/n ' ₁) when large, total reflection just occurs.For example with angle more than θ c, at the light of the lip-deep some Q institute incident of transparency carrier 105, just there is total reflection, can not shine air layer 106 sides.

Fig. 2 (a), (b) are the key diagrams that explanation transparency carrier 105 in above-mentioned light-emitting device has the light ejection efficiency under the supposed situation of multi-ply construction.In Fig. 2 (a), the refractive index of luminescent layer 103 is made as to n ' _k, the refractive index of air layer 106 is made as n ₀, the refractive index of a plurality of hyaline layers between luminescent layer 103 and air layer 106 from being made as n ' near a side of luminescent layer 103 _k-1, n ' _k-2, n ' ₁, the propagation orientation of the light that the some S in luminescent layer 3 sends (with the angle of the face normal of plane of refraction) is made as θ ' _k, the refraction angle of each plane of refraction is made as θ ' successively _k-1, θ ' _k-2, θ ' ₁, θ ₀, according to snell law (Snell ' s law) following formula, set up.

N ' _k* sin θ ' _k=n ' _k-1* sin θ ' _k-1=...=n ' ₁* sin θ ' ₁=n ₀* sin θ ₀(formula 1)

Therefore, following formula is set up.

Sin θ ' _k=sin θ ₀* n ₀/ n ' _k(formula 2)

Its result is expressed for (formula 2), and the snell law during only with luminescent layer 103 direct ingress of air layer 106 is relevant, and irrelevant with the refractive index of intervenient hyaline layer, at θ ' k>=θ _c=sin ^-1(n ₀/ n ' _k) time just there is total reflection.

The scope of the light that the expression of Fig. 2 (b) medelling ground is drawn from luminescent layer 103.The light of drawing is comprised in: take luminous point S as summit and with critical angle θ _c2 times be drift angle and centered by the z axle of the face normal along plane of refraction two pairs of cones 107,107 ' inside of axle.If the luminous transmissivity at the equicohesive light of comprehensive radiation and plane of refraction from a S is 100% under interior incident angle is take in critical angle, from the ejection efficiency η of luminescent layer 103, equal to cut the ratio of the area of sphere 108 to the surface area of sphere 108 by cone 107,107 ', can be expressed by following formula.

η=1-cos θ _c(formula 3)

Also have, because critical angle does not reach 100% with interior transmissivity, so actual ejection efficiency η is than 1-cos θ _clittle.In addition, the luminescence efficiency that is luminescent layer as the total efficiency of light-emitting component is multiplied by the value of above-mentioned ejection efficiency η.

For above-mentioned mechanism, in patent documentation 1, disclosed invention description is based on following principle: in organic EL, the object being suppressed for the total reflection on transparency carrier surface making when light penetrates from transparency carrier to atmosphere, at substrate interface and inner face or reflecting surface, form diffraction grating, light is changed to the incident angle of light lead surface, improve thus the ejection efficiency of light.

In patent documentation 2, describe and have in addition: for the planar emission apparatus that light ejection efficiency is good is provided, in organic EL, in the surface of transparency carrier, form a plurality of transparent thrusts, thereby can prevent from, at the interface of transparency carrier and air, reflection of light occurs.

Look-ahead technique document

Patent documentation

Patent documentation 1: Unexamined Patent 11-283751 communique

Patent documentation 2: JP 2005-276581 communique

Summary of the invention

The technical matters that invention will solve

Yet, the problem below existing in above-mentioned so existing light-emitting device.

In the use shown in Fig. 1 in the light-emitting device of existing organic EL, from the light ejection efficiency η maximum of luminescent layer 103, can not surpass 1-cos θ yet _cif the refractive index of luminescent layer 103 determined, the maximal value of light ejection efficiency is also just limited by beyond all doubt.For example, in (formula 2), if n ₀=1.0, n ' _k=1.457, critical angle θ _c=sin ^-1(n ₀/ n ' _k)=43.34 degree, the maximal value of light ejection efficiency is little of 1-cos θ _c=0.273 left and right, n ' _kbe reduced to 0.191 left and right at=1.70 o'clock.

In addition, in the disclosed technology of patent documentation 1, although can positively draw the light that become total reflection, also there is its contrary one side.; although exist under there is no the supposed situation of diffraction grating layer from the light of the some outgoing in luminescent layer at the plane of refraction (exit facet) of transparency carrier there is the situation of transmission, refraction than the little angle incident of critical angle; but when having diffraction grating layer therefore diffraction to occur, also exist the incident angle with respect to plane of refraction that the situation of total reflection occurs over critical angle.Therefore, the disclosed technology of patent documentation 1 cannot guarantee the raising of light ejection efficiency.In the disclosed technology of this external patent documentation 1, at whole light diffraction light that uniformly orientation of ormal weight moves, can occur.The light that includes such diffraction light, distributes to some extent because orientation causes light intensity, because the mobile range of ormal weight exists with ... outgoing light wavelength, therefore exists the look causing because of orientation unbalance.

In addition in the disclosed light-emitting device of patent documentation 1, from the light of extraneous (air layer side) incident by the regular property in surface of transparency carrier reflect, for the light of drawing from luminescent layer, form interference (so-called mapping: Ying り Write body), therefore need to the surface of transparency carrier, carry out the optical processing of antireflection film etc., this has raised goods cost.

On the other hand, in the disclosed light-emitting device of patent documentation 2, its object is that the light that prevents plane of refraction reflects, and the improvement of the light ejection efficiency that this structure brings is very little, but one, about twenty percent.

Technological means for technical solution problem

The present invention does in view of this point, its object is, a kind of thin slice and light-emitting device are provided, wherein, make also outgoing of the light to transparency carrier incident more than critical angle, thereby realize the significantly raising of light ejection efficiency, and can prevent mapping, suppress distribution and the look unbalance generation of the light intensity that causes because of orientation.

In order to solve above-mentioned problem, thin slice of the present invention, by making the face of a side and the transparent thin slice that luminophor adjacency is used, wherein, it is a plurality of tiny area δ below the above 1.5 μ m of 0.2 μ m that the face of the opposite side of described thin slice is divided into inscribe greatest circle diameter, and each tiny area δ by other two above the adjacency in described a plurality of tiny area δ and around, described a plurality of tiny area δ are by a plurality of tiny area δ that select at random with more than 40% ratio below 98% from described a plurality of tiny area δ _ba plurality of tiny area δ in addition _aform, at described tiny area δ _ain, disposing thickness is that d and effective refractive index are n _athe first microbody, at described tiny area δ _bin, disposing thickness is that d and effective refractive index are than n _alarge n _bthe second microbody.

According to such formation, from luminophor by the light of the face of the inner opposite side that incides thin slice of thin slice, even the angle incident of the face normal of take with respect to the face of opposite side more than critical angle, also can prevent that total reflection from occurring by formed surface structure by the tiny area by set on the face of opposite side, not only make a part for this light shine outside, and the light that reflexes to luminophor one side at the face by opposite side makes a part to outside outgoing while also inciding once again the face of opposite side of thin slice through the reflection of luminophor inside with regard to not there is total reflection.

Light-emitting device of the present invention; it has luminophor and set transparent protective seam in the light-emitting area of described luminophor; wherein; the face of described protective seam and face opposition side described light-emitting area adjacency; being divided into inscribe greatest circle diameter is a plurality of tiny area δ below the above 1.5 μ m of 0.2 μ m; and each tiny area δ by other two above the adjacency in described a plurality of tiny area δ and around, described a plurality of tiny area δ are by a plurality of tiny area δ that select at random with more than 40% ratio below 98% from described a plurality of tiny area δ _ba plurality of tiny area δ in addition _aform; At described tiny area δ _ain, disposing thickness is that d and effective refractive index are n _athe first microbody; At described tiny area δ _bin, disposing thickness is that d and effective refractive index are than n _alarge n _bthe second microbody.

According to more than because made to surpass the drawing repeatedly of light of critical angle, carried out, so can improve significantly light ejection efficiency.In addition,, because become the diffraction under random structure, so diffraction orientation does not have systematicness, can suppress distribution and the look unbalance generation of mapping and the light intensity that causes of orientation.

Accompanying drawing explanation

Fig. 1 means the key diagram of the situation of the cross-section structure of organic electroluminescent device and the propagation of light.

Fig. 2 (a) is the figure of the transparency carrier of explanation multi-ply construction, is (b) figure of the scope of the derivable light of explanation.

Fig. 3 (a) means the figure of variation of the step-like of refractive index, (b) means the figure that refractive index changes stably, (c) means the figure of the incident angle of plane of refraction and the relation of transmissivity, (d) means the figure of plane of refraction.

Fig. 4 (a) means the figure of the section of the light-emitting device that possesses the diffraction grating that has periodic structure at interface, (b) means the figure of the upper surface of (a).

Fig. 5 is the key diagram in the diffraction orientation of explanation based on diffraction grating.

Fig. 6 (a) means the figure of section of the light-emitting device of the projection on surface with random arrangement, (b) means the figure of the upper surface of (a).

Fig. 7 (a)～(h) is that explanation is at the figure of the boundary condition of the field of the light of plane of refraction.

Fig. 8 (a) is the figure that disposes pin hole (pinhole), is (b) figure that disposes phase shifter (phaseshifter).

Fig. 9 means that random arrangement has the figure of the corresponding transmissivity of incident angle of the plane of refraction of 180 degree phase shifters.

Figure 10 mean random arrangement have 180 degree phase shifters plane of refraction incident angle the corresponding description of test figure of rate that penetrates.

Figure 11 is for measuring the structural drawing of the experimental provision of the corresponding transmissivity of incident angle.

Figure 12 means the figure of the cross-section structure of organic electroluminescent device in the first embodiment and the propagation state of light.

Figure 13 (a) is the partial enlarged drawing of the surface structure in the first embodiment, is (b) the pattern figure of more wide region.

The key diagram of the field angle interdependence of the light of Figure 14 (a)～(d) mean surface structure institute outgoing from the first embodiment.

The key diagram of the field angle interdependence of the light of Figure 15 (a)～(d) mean surface structure institute outgoing from the first embodiment.

Figure 16 means the key diagram of incident angle-dependent of the transmissivity t of the surface structure in the first embodiment, (a) mean the key diagram of interdependence of the incident angle of primary transmissivity, (b) mean the key diagram of interdependence of the incident angle of secondary transmissivity.

Figure 17 means the description of test figure of incident angle-dependent of the transmissivity t of the surface structure in the first embodiment.

Figure 18 means the key diagram of the incident angle-dependent of drawing light quantity of the surface structure in the first embodiment, (a) mean primary key diagram of drawing the incident angle-dependent of light quantity, (b) mean secondary key diagram of drawing the incident angle-dependent of light quantity.

Figure 19 (a), (b) mean the key diagram of the light ejection efficiency of the surface structure in the first embodiment.

Figure 20 means the figure of the section with the light-emitting device of adjusting layer.

Figure 21 means the figure of the section of the light-emitting device that is also provided with surface structure at the interface with adjusting layer.

Figure 22 (a) means the key diagram of the light ejection efficiency of the surface structure in the second embodiment, (b) means the key diagram of the light ejection efficiency of the surface structure in the 3rd embodiment.

Figure 23 means the key diagram of the ejection efficiency in the second embodiment.

Figure 24 (a)～(e) is to the key diagram determining till the pattern of the surface structure in the 4th embodiment.

Figure 25 (a) means the figure of the first surface structure of the 6th embodiment, (b) means the figure of second surface structure.

Figure 26 (a) means the sectional view of the 8th embodiment, is (b) vertical view of the 8th embodiment.

Figure 27 (a) means the sectional view of the concrete structure of the 8th embodiment, is (b) vertical view along the section of the dotted line A shown in (a).

Figure 28 means the figure of incident angle-dependent of the transmissivity t of the 8th embodiment.

Figure 29 means the figure of the relation of light ejection efficiency when the outer shell 109 of the 8th embodiment is 0.1 μ m and size d.

The figure of light ejection efficiency when Figure 30 means the natural scale variation that makes the 8th embodiment and the relation of size d.

Figure 31 (a) means the sectional view of another concrete structure of the 8th embodiment, is (b) vertical view along the section of the dotted line A shown in (a).

Figure 32 (a) is the sectional view of other patterns of the 8th embodiment, is (b) vertical view of A section of other patterns of the 8th embodiment.

Figure 33 (a) and (b) mean the key diagram of the cross-section structure of the organic electroluminescent device in other embodiments and the propagation state of light.

Figure 34 is that surface structure is tessellated pattern figure.

Figure 35 means the key diagram of incident angle-dependent of the transmissivity t of the surface structure shown in Figure 34.

Figure 36 (a), (b) mean from the key diagram of the field angle interdependence of the light of gridiron pattern pattern surface structure institute outgoing.

Figure 37 (a)～(c) is the key diagram of method of the random configuration of explanation thrust.

Embodiment

Before the embodiment of explanation the present application, illustrate patent documentation 1 and patent documentation 2 etc. in advance on the basis of example until the research of the present application pass through.

Fig. 3 is the key diagram of the transmissivity of explanation plane of refraction (interface of transparent layer surface and air layer).From the inside of the hyaline layer 107 of refractive index 1.5, along paper direction, with angle θ, incide the plane of refraction 107a of hyaline layer 107 and the optical transmission rate of refraction occurs in air side (refractive index 1.0), relevant with polarized state of light.As a rule, index distribution along the face normal of plane of refraction 107a neighborhood, for this step-like shown in Fig. 3 (a), therefore P polarized light (oscillating component that electric field intensity is parallel with paper) illustrates the transmission characteristics of curve 108a, and S polarized light (oscillating component of electric field intensity and paper quadrature) illustrates the transmission characteristics of curve 108b.Although both are that the following characteristic of critical angle (=41.8 degree) is different in incident angle, if all become 0 over critical angle.

On the other hand, the surface part of hyaline layer 107 is formed to multi-ply construction, index distribution becomes under the supposition of cone-shaped such shown in Fig. 3 (b), P polarized light demonstrates the transmission characteristics of curve 108A, and S polarized light demonstrates the transmission characteristics of curve 108B.If all become 0 this point and do not change although surpass critical angle, the transmissivity below critical angle approaches 100%, is similar to take the shape of the step function that critical angle is boundary.In Fig. 3 (b), from 1.5 till 1.0 calculate being the structure of 50 layers of film-stack of thickness 0.01 μ m of 0.01 deviation in refractive index, but obtained under the mild situation of the gradient of the variations in refractive index of thickness direction, the difference of P polarized light, S polarized light disappears, and the curve approximation of the corresponding transmissivity of incident angle is in the result of step function.

In order not there is not total reflection, what need to prepare is to make the incident angle of light of incident plane of refraction below critical angle.One of method of preparing as this, take patent documentation 1 as example, for the light-emitting device shown in Fig. 4, inquires into, and has used the organic EL that is provided with diffraction grating 209 at the interface of transparency carrier 205 and transparency electrode 204 in this light-emitting device.

As shown in Fig. 4 (a), on substrate 201, stacked above one another electrode 202, luminescent layer 203, transparency electrode 204, diffraction grating layer 209 are provided with transparency carrier 205 on diffraction grating layer 209.Diffraction grating layer 209 and transparency carrier 205 between there is the concavo-convex periodical configuration that x direction, y direction are spacing Λ, the square that is shaped as this wide w shown in Fig. 4 (b) and this protuberance of protuberance are arranged in plover trellis.Between electrode 202, transparency electrode 204, apply voltage, luminous by the some S of the inside of luminescent layer 203, this light directly or seeing through transparency electrode 204 and seeing through diffraction grating layer 209 and carry out diffraction after electrode 202 reflections.For example, at the light 210a from a S outgoing, diffraction grating layer 209, there is not diffraction but in straightaway supposition situation, as light 210b at the plane of refraction 205a of transparency carrier 205 with angle incident more than critical angle and total reflection occurs, but in fact because there is diffraction in diffraction grating layer 209, so can be as light 210c, the incident angle of birefringence face 205a can be less and seen through than critical angle.

The diffraction orientation of the diffraction grating according to Fig. 5 explanation based on above-mentioned.Investigation is from refractive index n _athe inside of hyaline layer 207 along paper direction the point O on the plane of refraction 207a of hyaline layer 207 with angle θ incident and at refractive index n _bthe light of wavelength X of hyaline layer 206 side diffraction.At plane of refraction 207a, being formed with along paper is the diffraction grating of spacing Λ.Draw the radius n centered by an O on paper _acircle 211 and radius n _bcircle 212.Make incident vector 210i (take on circle 211 circumference for starting point and with angle θ the vector towards an O) the orthogonal projection vector to plane of refraction 207a (vector from intersection point A towards an O) be made as 210I, and according to the mode that its orthogonal projection 210R and vector 210I are equal to, draw justifying the vector 210r on 212 circumference with terminal as starting point take an O.The vector (grating vector) of intersection point C as starting point, value q λ/Λ take in investigation.Wherein, q is the order of diffraction time (integer).Vector 210D while drawing q=1 in figure, and take its terminal B as intersection point and take an O as the vector 210d that starting point has terminal on circle 212 circumference drawn.According to the method for drawing, the position angle of vector 210r (with the angle of plane of refraction normal) represented by following formula.

(formula 4)

Here it is snell law.On the other hand, give the position angle of vector 210d in the orientation of diffracted ray (with the angle of plane of refraction normal) represented by following formula.

(formula 5)

Wherein, the angle in this situation of Fig. 5 because stride across z axle (by the plane of refraction normal of an O), so defined by negative.

That is, diffracted ray can carry out orientation by the amount of q λ/Λ from refracted ray and moves.In Fig. 4, the light 210b under the hypothesis that diffraction does not occur is equivalent to refracted ray, and the light 210c of institute's diffraction carries out orientation from light 210b by the amount of q λ/Λ and moves, thereby avoids the total reflection on plane of refraction 205a.Therefore also think, because light that should total reflection can be drawn, so compare with the organic EL light emitting device without diffraction grating layer, can predict the raising of light ejection efficiency.

Yet, in the situation that in investigating Fig. 4 (a) from the light 210A of a S outgoing, find following problem.If there is not diffraction and straightaway in supposition light 210A in diffraction grating layer 209, as light 210B, can with the angle incident below critical angle and at plane of refraction 205a, occur to reflect and see through at the plane of refraction 205a of transparency carrier 205, but in fact because there is diffraction in diffraction grating layer 209, so as light 210C, the incident angle of birefringence face 205a can be larger than critical angle, and just there is total reflection at plane of refraction 205a with angle incident more than critical angle.So, even if diffraction grating layer 209 is set, also may not guarantee the raising of light ejection efficiency.

In addition, in having used the light-emitting device of the organic EL shown in Fig. 4, can occur by the amount of q λ/Λ, to have carried out the diffraction light that orientation moves without exception about whole light.The light that comprises such diffraction light, because orientation causes distributing to some extent in light intensity, because mobile range q λ/Λ exists with ... the wavelength X of emergent light, so because the orientation of light outgoing exists look unbalance.That is, can see the light of different colours according to view direction, it is not suitable for display applications certainly, even also imappropriate as light source.

Secondly, take patent documentation 2 as example, for shown in Fig. 6, used the light-emitting device that the organic EL of thrust 315 is set on the surface of transparency carrier 305 to study.As shown in Fig. 6 (a), on substrate 301, stacked above one another electrode 302, luminescent layer 303, transparency electrode 304, transparency carrier 305, form a plurality of thrusts 315 at the surperficial 305a of transparency carrier 305.Thrust 315 is the quadrangular prism shape of wide w, high h, as shown in Fig. 6 (b), is configured in the upper random position of 305a, transparency carrier surface.The scope of the size of w in 0.4～20 μ m, the scope of the size of h in 0.4～10 μ m, such thrust 315 is with 5000～1000000/mm ²the density of scope form.Between electrode 302, transparency electrode 304, apply voltage, luminous by the some S of the inside of luminescent layer 303, directly or seeing through transparency electrode 304 after electrode 302 reflections, its part is drawn out to the external world by thrust 315 to this light 310d as 310f.Actual thrust 315 not only can be by side etching (side etching) according to processing with regard to thinner mode the closer to front end, even and because do not implement side etching near the also value centre of desirable transparency carrier 305 and air of effective refractive index, so can make equivalently index distribution gently change.Therefore formed distribution is close to this index distribution shown in Fig. 3 (b), so utilize thrust 315 can partly prevent this reflection of light shown in 310e, result is to improve the ejection efficiency of light.In addition, even more than the size of thrust 315 is set as wavelength, because thrust 315 is random alignment, so the interference of light that still can suppress to draw.

Yet, in the light-emitting device of the structure shown in Fig. 6, if the effect of thrust is the reflection of advocating among patent documentation 2 and prevents, more known according to curve 108a, the 108b of Fig. 3 (c) and curve 108A, 108B, the raising of transmissivity only limits to the light below critical angle, the improvement of the ejection efficiency of light rests on one, about two one-tenth, can't see very large improvement.

Carry out above such research and based on this, the present application person for how reducing the light quantity that is totally reflected at plane of refraction, how to increase drawn light quantity and carried out further research repeatedly.Initial as further research is the boundary condition of the light of research plane of refraction.

Fig. 7 medelling ground represents the boundary condition of the field of the light in plane of refraction, and the light of investigating width W incides the situation of plane of refraction T.According to Maxwell's equation, about electric field intensity or magnetic vector, along pressing from both sides every plane of refraction T, the integration of the path A of circuit is 0.But inside, circuit path does not have electric charge and light source, along the electric field intensity of plane of refraction T or the intensity of magnetic vector, phase place, be continuous, become precondition.

In the situation that width W as shown in Fig. 7 (a) is fully large, compared with the width s along plane of refraction, can littlely arrive negligible degree, the only composition along plane of refraction within remaining contour integral with the amplitude t of plane of refraction quadrature.According to this relation, can try to achieve, folder under plane of refraction electric field intensity or magnetic vector continuous.What utilize that this successional relation derives is exactly the formula of Fresnel, by this formula can get across completely reflection, the rule of refraction and the phenomenon of total reflection etc.

As Fig. 7 (b), if the width W of light is little to the decades of times of wavelength, can not ignore width t.At this moment, if contour integral A is divided into B and C (with reference to Fig. 7 (c)), wherein contour integral B thinks 0 because be comprised in light beam.With regard to remaining contour integral C, because the electric field intensity outside light beam or magnetic vector are 0, so only there is the integrated value residue (with reference to Fig. 7 (d)) of the path P Q in light beam.Therefore contour integral C is not 0, on calculating with circuit path in the light that sends of equal value.In addition, if little 1/10 left and right to wavelength of the width W of light, as shown in Fig. 7 (e), because contour integral C and C ' approach, path P Q and Q ' P ' are overlapping, so the contour integral after C and C ' are combined becomes 0, in circuit path, can not send light.

On the other hand, investigate in the situation that as Fig. 7 (f) the light with the phase differential of π along plane of refraction, cross over side by side the contour integral A of these light beams.In this case, if the width W of light is little to the decades of times of wavelength, can not ignore width t.At this moment, if contour integral A is divided into B, C and B ' (with reference to Fig. 7 (g)), wherein B, B ' so become 0 because be comprised in light beam.In remaining contour integral C, along the composition of plane of refraction, can ignore, only have the path P Q of boundary and the integrated value of Q ' P ' residue (with reference to Fig. 7 (h)) along two light beams.Because the integration in the path Q ' P ' of the phase place of light beam is π field equals the path P of the field that the phase place of light beam is 0 ' integration in Q ', so contour integral C becomes the size of 2 times of the integration in path P Q, on calculating with circuit path in the light that sends of equal value.Therefore, be not only the light of narrow width, even if the light that phase place is different via narrow degree is wide is side by side time, near the boundary of width, can send light (is not in fact luminous yet, but in actual effect, be equal to the phenomenon of luminous performance, be similar to early stage this phenomenon of boundary diffraction of advocating before diffraction theory is set up, so be called boundary diffraction effect).

If have luminously under incident condition in plane of refraction T whatever on plane of refraction, this light is propagated in two sides' of plane of refraction medium at folder.Even think more than critical angle incident light, if calculated, above at plane of refraction, produce luminously, there is not total reflection yet, but be revealed as transmitted light.Therefore, the present application person, according to this investigation result, study a kind of structure of plane of refraction as follows, and it is still having light transmissive phenomenon to occur practically for making under critical angle.

Example as strong embodiment boundary diffraction effect, as shown in Figure 8, the boundary face of the transparency carrier loading at luminophor and air, (a) arranges pin hole and the part beyond it is carried out shading and become pin hole light (only having light to exist) in white quadrilateral; (b) phase shifter 18 of random arrangement 180 degree on the gridiron pattern of separating by width w.Also having, be to study with pin hole at first, but pin hole almost can not carry out drawing of actual light, therefore for being considered to demonstrate the phase shifter of drawing the random arrangement of characteristic with the equal light of pin hole, is also studied.

Fig. 9 means the key diagram of the incident angle-dependent of the transmissivity t in plane of refraction in the structure shown in Fig. 8, making light wavelength is 0.635 μ m, in the transparency carrier of refractive index 1.457 light of light quantity 1 at the boundary face with air with angle θ (with the angle of plane of refraction normal) incident, as what kind of the lower expression of parameter (w=0.1,0.2,0.4,0.6,0.8,1.0,2.0,4.0,20.0 μ m) has measure for the first time, be mapped to air side (because pin hole light also demonstrates and the identical characteristic of 180 degree phase shifter, so substituted by 180 degree phase shifters) take width w.The characteristic of the w=20 μ m close with the condition of Fig. 7 (a) is: if surpass critical angle (43.34 degree), transmissivity is roughly 0.If w is little of 0.4～1.0 μ m, under the boundary diffraction effect illustrating at Fig. 7 (d), (h), even if surpass critical angle, still there is very large transmissivity.If further reduce w (w=0.1,0.2 μ m), as illustrated in Fig. 7 (e), under all incident angles, transmissivity all approaches 0.Also have, because Fig. 9 is the analysis result of the wave equation (so-called scalar wave equation formula) based on Helmholtz, so the difference of P polarized light and S polarized light does not represent.

The experimental result of the incident angle-dependent of the t of transmissivity for the first time that Figure 10 means in the incident of P polarized light.Because the making of fine phase shifter 18 is had any problem in practice, so with mask (be equal to so-called on the gridiron pattern of being separated with width w random arrangement the parts of the parts of photomask, random arrangement pin hole light) substituted to test, in this mask, allow the part of phase place 0 degree see through, by photomask (Cr film), covered the part of phase place 180.In the mask pattern of actual fabrication, wide w is 0.6,0.8,1.0,2.0,5.0 μ m.Experimental provision is as shown in figure 11 by forming as follows: semiconductor laser (wavelength 0.635 μ m), triangular prism 58 (BK7), mask substrate 59 (synthetic quartzs, refractive index 1.457, back side formation mask pattern), condensing lens system 50, photodetector 51, and folder makes triangular prism connect airtight the surface in mask substrate every the matching fluid 52 of refractive index 1.51, on one side from one side, triangular prism side instrumentation position angle incident laser, the transmitted light leaking from rear side is collected by condensing lens system 50, by photodetector 51, measures transmission light quantity.In the situation of mask, the part of the photomask that whole 1/2 area is suitable is subject to shading, transmission light quantity with used phase shifter be in a ratio of 1/2, therefore as transmissivity t, by light quantity (whole 1/2 the light quantity) normalization of inciding the part that there is no photomask.Experimental result is consistent with the analysis result shown in Fig. 9, surpasses critical angle (43.34 degree) still have very large transmissivity even known, and less this tendency of w is stronger.

Result based on such, the present application person further study, the light-emitting device of reaching not yet up to now that makes the ejection efficiency of light improve until expected preventing total reflection tremendously.

Below, based on accompanying drawing, explain embodiments of the present invention.In following accompanying drawing, in order to make interest of clarity, by same reference marks, represent to have in fact the inscape of identical function.

(the first embodiment)

Based on Figure 12～19 (a), (b), the first embodiment is described.

Figure 12 represents to have used in the first embodiment the cross-section structure of light-emitting device and the propagation state of light of organic EL.Stacked above one another electrode 2, luminescent layer 3, transparency electrode 4 on substrate 1 form transparency carrier (transparent protective seam) 5 on transparency electrode 4.Substrate 1, electrode 2, luminescent layer 3, transparency electrode 4 form luminophor.On the surface of transparency carrier 5, be formed with by tiny area differentiationization and there is fine concavo-convex surface structure 13.

Between electrode 2, transparency electrode 4, apply voltage, point S by the inside of luminescent layer 3 is luminous, this light directly or seeing through transparency electrode 4 after electrode 2 reflection, point P on the surface structure 13 on transparency carrier 5 surfaces with angle θ incident, shines air layer 6 sides at this point via surface structure 13 diffraction with respect to surperficial face normal.

If the refractive index of air layer 6 is n ₀, the refractive index of transparency carrier 5 is n ₁, incidence angle θ is than critical angle θ _c=sin ^-1(n ₀/ n ₁) should there is total reflection when large.But, because have surface structure 13 on transparency carrier 5 surfaces, so even at a Q light with critical angle θ _ccan there is not total reflection in above angle incident, but diffraction occurs, and shines air layer 6 sides (primary light is drawn) yet.Also have, in a part for Q light, can reflect, but the composition of this reflection is after electrode 2 reflections, can incide once again the some R on surface structure 13, its part shines air layer 6 sides (secondary light is drawn), remaining reflection.Above process infinitely repeats.

At this, if investigate the light-emitting device that uses the existing organic EL that there is no surface structure 13, with angle more than critical angle light generation total reflection from transparent substrate side incident at the interface of transparency carrier and air layer, even if it is reflected by electrode, once again at the interface of transparency carrier and air layer also again with angle incident more than critical angle, therefore drawing of later for the second time light can not occur, this point is different from present embodiment.

Below, for the feature of present embodiment, be that surface structure 13 at length describes.

Figure 13 illustrates the pattern figure of the surface structure 13 of the first embodiment.The left side of Figure 13 (a) is vertical view, and right side is the A-A sectional view of vertical view.Shown in Figure 13 (a), surface structure 13 is the surface of transparency carrier 5 to be seamlessly divided into the wide w gridiron pattern of (being called boundary width) (foursquare tiny area δ) and lattice (tiny area δ) are one by one protruding ((the tiny area δ of the 13a in figure ₁), be the lattice of grey) or protruding with respect to this be recessed ((the tiny area δ of the 13b in figure of relativity ₂), for white lattice) structure that distributes randomly in each mode of 50% of ratio, example during w=0.4 μ m shown in Figure 13 (b) (black correspondence is protruding, white corresponding recessed).Protruding projecting height is seen as d from recessed bottom.Tiny area δ by other a plurality of tiny area δ in abutting connection with and by around, tiny area δ ₁than tiny area δ ₂more outstanding to the surperficial top of transparency carrier 5.At this, if at tiny area δ ₁with tiny area δ ₂, perpendicular to the relevant centre position of the surperficial direction of transparency carrier 5, determine the reference field surperficial parallel with transparency carrier 5, tiny area δ ₁from reference field, give prominence to upward d/2, tiny area δ ₂from the reference field d/2 that caves in downwards.Or, at transparency carrier 5 and the boundary face of air 6, exist the upper surface of a plurality of depressions (white part) and depression part to be in addition present on the same face, the degree of depth of depression is respectively identical in fact d, using the bottom surface of this depression as the first reference field, the first reference field is divided into and has 1.5 * 1.5 μ m ²following of the same area a plurality of tiny area δ, or the bottom surface of depression is the continuous shape of plural tiny area δ or the shape of only having a tiny area δ, also can say that depression is configured on the first reference field randomly.Also have, the first reference field and above-mentioned reference field are different faces.

Tiny area δ is respectively tiny area δ ₁or tiny area δ ₂probability, be for example 50% in the present embodiment.Therefore, in tiny area δ, tiny area δ ₁or tiny area δ ₂can be continuously in abutting connection with existing more than 2.In this case, at continuous tiny area δ ₁or tiny area δ ₂between do not form boundary, boundary is imaginary.But, in this situation, due to tiny area δ ₁or tiny area δ ₂continuously, the boundary in these regions has also just disappeared, and can say that the surface of transparency carrier 5 is divided with tiny area δWei base.

The formation of surface structure 13 also can be carried out by the following method: make and form irregular mould through etching, its shape is transferred on the resin of sheet through extruding, using this thin slice as transparency carrier 5, via tack coat, make it to be fitted in transparency electrode 4.In this case, transparent thin slice is equal to transparency carrier 5.In addition, also can adopt on the surface of the surface of thin slice or the transparency carrier 5 that forms as protective seam directly by etching etc. and form concavo-convex method.

By the light of such random pattern diffraction its to propagate orientation be also random, therefore there is not the distribution of light-emitting device described in patent documentation 1 light intensity such, that cause because of orientation, the look also not causing because of orientation is unbalance.In addition, from the light of extraneous (air layer side) incident, the surface structure 13 of transparency carrier 5, reflect, but this reflected light is at random orientation generation diffraction, therefore there is no extraneous picture mapping (mirroring), the optical processing that does not need antireflection film etc., can suppress lowly by goods cost.Figure 14～Figure 15 means the key diagram of analysis result of drawing the field angle interdependence of light from the surface structure outgoing of the first embodiment primary, and discrepancy in elevation d=0.7 μ m, usings wavelength X and boundary width w as Parametric Representation.Figure 14 (a) is the condition of λ=0.450 μ m, w=0.5 μ m, Figure 14 (b) is the condition of λ=0.635 μ m, w=0.5 μ m, Figure 14 (c) is the condition of λ=0.450 μ m, w=1.0 μ m, Figure 14 (d) is the condition of λ=0.635 μ m, w=1.0 μ m, Figure 15 (a) is the condition of λ=0.450 μ m, w=1.5 μ m, Figure 15 (b) is the condition of λ=0.635 μ m, w=1.5 μ m, Figure 15 (c) is the condition of λ=0.450 μ m, w=2.0 μ m, and Figure 15 (d) is the condition of λ=0.635 μ m, w=2.0 μ m.The vector that point on initial point and curve is linked represents light intensity and the outgoing orientation of emergent light, the length respective light intensities of vector, the corresponding outgoing orientation, orientation of vector.The orientation of longitudinal axis corresponding surface normal axis, the orientation of axle in transverse axis corresponding surface, solid line is that the interior axle of face is along the characteristic of the section (the longitude orientation of 0 degree, 90 degree) of the x axle in Figure 13 (b) or y axle, dotted line be in face axle along the characteristic of the section (the longitude orientation of 45 degree, 135 degree) of the straight line of y=x or y=-x, (it is consistent that the results in 90 degree orientation and 0 are spent orientation, the result in 135 orientation is consistent with 45 degree orientation, therefore omitted).When boundary width w=0.5,1.0 μ m, solid line, dotted line all illustrate smooth change (that is, follow the intensity difference of parallax few) with respect to drift angle (latitude), and both are consistent.If increase w, become w=2.0 μ m, the change of the intensity with respect to drift angle at the neighborhood of face normal direction becomes large; During the μ m of λ=0.450, it is large that the difference between solid line, dotted line also becomes.W=1.5 μ m is the critical condition that intensity change occurs.Therefore known, the light intensity of face normal direction is strong, mild with respect to the change of drift angle (latitude), and the few field angle interdependence of light intensity difference of longitudinal can be the condition acquisition below 1.5 μ m at boundary width w.

Figure 16 is the key diagram of incident angle-dependent of transmissivity t of the surface structure 13 of explanation the first embodiment, light in the interior light quantity 1 of transparency carrier 5 incides surface structure and has for the first time the light how to measure to shine air 6 sides with angle θ (with the angle of plane of refraction normal), is illustrated in Figure 16 (a).Figure 16 (b) represents, by surface structure 13 reflections situation of incidence surface structure 13 once again after electrode 2 reflections, represents the incident angle-dependent of secondary transmissivity.No matter being which figure, is all refractive index ns of transparency carrier 5 ₁=1.457, the refractive index n of air 6 ₀=1.0, light wavelength λ=0.635 μ m, tiny area δ ₁with respect to tiny area δ ₂projecting height d=0.70 μ m, tiny area δ ₁area ratio (as protruding ratio) P=0.5, the width w of surface structure of take is parameter (w=0.1,0.2,0.4,0.6,0.8,1.0,2.0,4.0 μ m).Also have, projecting height d=0.70 μ m, is equivalent in vertical incidence at the transmitted light of recess and the condition (d=λ/2 (n of π phase differential occurs at the transmitted light of protuberance ₁-n ₀)).

In Figure 16 (a), except the result difference of w=0.1,0.2 μ m, all approach the result (Fig. 9) in 180 degree phase shifters, even if surpass critical angle, also have very large transmissivity.Figure 17 means the experimental result of incident angle-dependent of the transmissivity t of P polarized light incident.In fact by electronic beam method, on quartz base plate, form the concavo-convex random pattern of depth d=0.70 μ m, boundary width w=0.4 μ m, use the determinator shown in Figure 11 to test.Experimental result is consistent with the analysis result height shown in Figure 16 (a), surpasses critical angle (43.34 degree) still have very large transmissivity even known.As explanation before present embodiment, if under what kind of incident condition of plane of refraction and all have luminous (so-called boundary diffraction effect) of equal value on plane of refraction, this light is propagated in both sides' the medium that clips plane of refraction.Even if this shown in Figure 16 surpasses critical angle, light is the phenomenon of transmission still, and the luminous condition that can produce equivalence on this plane of refraction also can illustrate.

If supposition luminously makes light become spherical wave in transparency carrier 5 and diffusion equably by putting, the summation of the light quantity according to luminous azimuth angle theta (consistent with aforesaid incidence angle θ) and between θ+d θ, is just directly proportional to sin θ d θ.Therefore, drawing light quantity is directly proportional to the value that the transmissivity t shown in Figure 16 (a), (b) is multiplied by sin θ.Figure 18 (a), (b) mean the key diagram of the incident angle-dependent of drawing light quantity of the surface structure of the first embodiment.; the light of the light quantity 1 that a bit (being actually the point in luminescent layer) in transparency carrier 5 sent has how much light to shine air layer 6 sides with angle θ (with the angle of plane of refraction normal) incidence surface structure to be illustrated in Figure 18 (a) for the first time; at Figure 18 (b), represent; in surface structure 13, carry out primary event and after electrode 2 reflections, reenter the situation of reflective surface structure 13, represent secondary incident angle-dependent of drawing light quantity.

If will draw light quantity, by incidence angle θ, carry out integration, can access light ejection efficiency.Figure 19 (a), (b) mean the key diagram of light ejection efficiency of the surface structure 13 of the first embodiment, under the identical condition of the condition with Figure 16, the boundary width w of surface structure 13 are set on transverse axis in the lump.In Figure 19 (a), except the projecting height d=0.70 μ m of surface structure 13, (the primary smooth ejection efficiency η of light ejection efficiency when d=0.1,0.30,0.50,1.40 μ m are also shown ₁), be illustrated in addition and there is no the optical attenuation in coming and going such as the reflection loss of the absorption of transparency electrode 4 and electrode 2, by surface structure 13 reflections, after electrode 2 reflections, reentered the light ejection efficiency that reflective surface constructs at 13 o'clock (light ejection efficiency η for the second time ₂).Curve 5a, 5A be respectively under d=0.70 μ m for the first time and secondary smooth ejection efficiency, curve 5b, 5B be respectively under d=0.50 μ m for the first time and secondary smooth ejection efficiency, curve 5c, 5C be respectively under d=0.30 μ m for the first time and secondary smooth ejection efficiency.Curve 5g, 5G be respectively under d=0.10 μ m for the first time and secondary smooth ejection efficiency, owing to comparing with other degree of depth, light ejection efficiency is little, so need projecting height d, is more than 0.20 μ m.In addition, as shown in curve 5h, if reach the multiple above (d >=1.4 μ m) of visible wavelength, at width w, be the region below 1.5 μ m, primary efficiency is greatly deteriorated, and therefore preferably projecting height d is below 1.4 μ m.Therefore, the scope of the recommendation of d in 0.2～1.4 μ m.If be more generally, n if establish the refractive index of transparency carrier 5 ₁, the refractive index of air 6 is n ₀(still, the medium contacting with transparency carrier 5 can not be also air, as long as the refractive index n of this medium ₀than the refractive index n of transparency carrier 5 ₁little), the centre wavelength of the spectrum of light is λ, λ/(n ₁-n ₀)>=d>=λ/6 (n ₁-n ₀) the condition recommendation that is the discrepancy in elevation.

During the μ m of d≤0.70, it is very big that primary smooth ejection efficiency all becomes when boundary width is 0.2～1.4 μ m; If reduce or strengthen w, be gradually to 0.27 (the so-called value being provided by (formula 3), light ejection efficiency when surface is minute surface).Secondary smooth ejection efficiency all reaches maximum value between the μ m of w=0.10～2.0, if increase w, is gradually to 0.00 (not embodying in the scope of Figure 19); During the μ m of w≤0.10, along with w diminishes and converges to 0.00.

As a reference, curve 5d, the 5D of Figure 19 (b) represent, surface structure 13 is not set at tiny area δ ₁when middle setting makes the phase place of light change the phase shifter of 180 degree for the first time with secondary smooth ejection efficiency.In the surface structure 13 of present embodiment, there is phase differential in the propagation light of recess and protuberance during the propagation with its discrepancy in elevation part, and with respect to this, phase shifter is that imaginary propagation distance is 0 the parts of phase differential to occur.The in the situation that of phase shifter, if increase boundary width w, for the first time, secondary smooth ejection efficiency is gradually to respectively 0.27,0.00, this is identical with surface structure 13; If but be reduced to below 0.3 μ m, to be not only for the second time, primary smooth ejection efficiency also becomes 0 (its reason is illustrated by Fig. 7 (e)).Under the condition of the surface structure 13 of present embodiment below boundary width 0.4 μ m, can obtain one of reason of the light ejection efficiency higher than phase shifter, be considered to protuberance and brought into play effect as optical waveguide.

If, the surface of transparency carrier 5 that see from transparency carrier 5 and the round light transmission between electrode 2 are made as τ, considered that the secondary smooth ejection efficiency of the optical attenuation in coming and going is τ * η ₂.Light draw not only carry out once, twice, and infinitely repeated, if suppose that its pass is Geometric Sequence, be η for the first time ₁, be τ * η for the second time ₂, can envision the n time for η ₁* (τ * η ₂/ η ₁) ^n-1.Therefore to adding up to that the light of the n time is drawn:

[formula 1]

${\mathrm{\η}}_1\×\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{(\mathrm{\τ}\×{\mathrm{\η}}_2/{\mathrm{\η}}_1)}^{k-1}$ (formula 6)

When unlimited, be gradually to η ₁/ (1-τ * η ₂/ η ₁).

In Figure 19 (a), if seen by curve 5a, 5A (d=0.70 μ m), during w=0.60 μ m, η ₁=0.318, η ₂=0.093; If τ=0.88, can access 0.428 light ejection efficiency.During w=1.00 μ m, η ₁=0.319, η ₂=0.102, can access 0.444 light ejection efficiency.On the other hand, the existing light-emitting device shown in Fig. 1, Fig. 3 (a), η ₁=0.274, η ₂=0, be all 0 for the second time later, add up to 0.274.Therefore known, under the condition of w=0.60 μ m, the light-emitting device of present embodiment is 1.56 times of the light-emitting device shown in Fig. 3 (a), at the next light ejection efficiency that can realize 1.62 times of condition of w=1.00.So, by making w than 0.2 μ m large (if usually performance is that it is more than 0.2 μ m making with the maximum diameter of the circle of tiny area δ inscribe), can realize the significantly raising of light ejection efficiency.

Next, how the light ejection efficiency of the surface structure 13 in investigation present embodiment exists with ... wavelength.

Curve 5a ', 5A ', 5h ', the 5H ' of Figure 19 (a) is illustrated under the condition of wavelength 0.45 μ m, d=0.70 μ m, 1.40 μ m corresponding for the first time with secondary smooth ejection efficiency.The result of these characteristics and wavelength 0.635 μ m is unanimous on the whole, therefore known, can reduce to follow the wavelength difference in visible ray and the variation of the ejection efficiency that comes.

So, even the shape that the surface structure of present embodiment 13 is single (d and w), for the whole optical wavelength in visible ray, also can obtain the light ejection efficiency that approaches optimum value, while therefore this being configured to the display surface of display equipment, need to individually not change shape for these three kinds of pixels of RGB, the adjustment in the time of can making form and assemble is simplified significantly.

In addition, in organic EL, on transparency electrode 4, be provided with for regulating light between transparency carrier 5 and electrode 2 at the transparent adjustment layer of the light transmission coming and going.In this case, transparency carrier 5 loads in adjusting layer upper (that is, can be called luminophor at interior organic EL by comprising adjustment layer), if but the refractive index n of transparency carrier 5 ₁than the refractive index n of adjusting layer ₁' little, the boundary face, particularly n that between transparency carrier 5 and adjustment layer, exist total reflection to occur ₁'-n ₁during > 0.1, more can not ignore its impact.Figure 20 represents the propagation state of light at this moment.

In Figure 20, by refractive index n ₂the light that sends of the some S of inside of luminescent layer 3, directly or seeing through transparency electrode 4 and seeing through refractive index n after electrode 2 reflections ₁' adjustment layer 15, and the some P ' on boundary face 15a reflects and see through refractive index n ₁transparency carrier 5 and the some P on the boundary face of transparency carrier 5 and air 6 shine air 6 sides.At this n ₁'>=n ₂> n ₁> 1.0.Also has n ₁' also can compare n ₂little, but at this moment between transparency electrode 4 and adjustment layer 15, there is total reflection.In transparency carrier 5, with the boundary face of air 6, be formed with the surface structure 13 of present embodiment, even therefore surpass the light of critical angle, also can be drawn out to air layer 6 sides.But, due to n ₁' > n ₁relation, at boundary face also can there is total reflection in 15a.That is, compare with to the incident of a P ' and incident angle larger to a Q ' enter to hit generation total reflection, this light and electrode 2 between repeatedly there is total reflection, can not be drawn out to air 6 sides.

In this case, as shown in figure 21, the surface structure 13 ' of present embodiment is also set at the boundary face of adjusting layer 15 and transparency carrier 5, thereby the incident light that surpasses critical angle in this face can be drawn out to air 6 sides.That is,, under the effect of surface structure 13 ', even if surpass the incident to Q ' point of critical angle, can there is not total reflection yet; The composition being reflected by this face is after electrode 2 reflections, and incidence surface is constructed the some R ' on 13 ' again, and its part can shine air 6 sides via surface structure 13, and above process infinitely repeats.The structure of Figure 21 is by the labyrinth of the irregular surface structure 13 of tool, the 13 ' dual formation, and transparency carrier 5 can use the material that refractive index is low, has advantages of the selection face of expanding material.

Also have, according to (formula 6), if the round light transmission τ between transparency carrier 5 and electrode 2 is large, light ejection efficiency increases.Actual luminescent layer 3 is by the encirclements such as a plurality of hyaline layers such as adjustment layer 15 except electrode 2 and transparency electrode 4, above-mentioned, and the design of these films (refractive index of the film that comprises luminescent layer 3 and the decision of thickness) should be carried out according to making aforesaid optical transmission rate τ reach maximum mode.At this moment, the reflection of surface structure 13 is because the distribution of phase place is random, so catoptrical, overlappingly with incoherent (incoherent), treat (not that amplitude is added, but intensity addition).That is, the surperficial reflections affect of transparency carrier 5 can be ignored, and in hypothesis, reflectivity is 0%, transmissivity is 100% to treat.Under this condition, from transparency carrier 5, light is sent, this light is is repeatedly come and gone comprising luminescent layer 3 in interior multilayer film, so that return to the overlapping light quantity of the complex light amplitube of transparency carrier 5, reach maximum, as condition, decide refractive index and the thickness of each film.

(the second embodiment)

Based on Figure 22, Figure 23, the second embodiment is described.Also having the second embodiment is that the pattern of surface structure 13 is different from the first embodiment, and other structures are identical with the first embodiment, for its explanation of common incomplete structure.

In the second embodiment, not using surface structure as protruding ratio P with as recessed ratio 1-P, be fixed as 0.5, and be made as P=0.4～0.98.That is, tiny area δ ₁(outstanding region upward) exists 40～98%, tiny area δ ₂(depression) exists 60～2%.

Figure 22 (a) is the figure of light ejection efficiency of the surface structure of explanation present embodiment, is illustrated in the refractive index n of transparency carrier 5 ₁=1.457, the refractive index n of air 6 ₀=1.0, the boundary width w that the projecting height d=0.70 μ m of light wavelength λ=0.635 μ m, surface structure and transverse axis are made as surface structure and ratio P=0.2,0.4,0.6, the light ejection efficiency (the 1st time and the 2nd time) of 0.8,0.9 o'clock.Curve 6a, 6b, 6c, 6d, 6e and 6A, 6B, 6C, 6D, 6E are respectively P=0.2,0.4,0.6, the light ejection efficiency of 0.8,0.9 o'clock.Curve 27a, the 27A of Figure 23 are under these conditions, boundary width w=1.0 μ m, and making protruding ratio P is the light ejection efficiency drawn out of transverse axis (for the first time and for the second time).

According to Figure 22 (a), in primary smooth ejection efficiency, at the Zone Full of w, the characteristic of ratio P=0.2 is minimum, and during the μ m of w≤2, the characteristic of P=0.6 provides maximal value.In secondary smooth ejection efficiency, in the scope of w≤4 μ m, the characteristic of P=0.9 is maximum, and the characteristic of P=0.2 is minimum.

According to the curve 27a of Figure 23, in primary light is drawn, the ratio P of the concavo-convex area ratio of domination is set in to 0.4～0.8 scope centered by 0.6, can further improve light ejection efficiency.This be considered to due to the cause that protuberance within the scope of this plays a role effectively as optical waveguide (P≤0.2 o'clock, the Area Ratio of protuberance that forms waveguide is few; P >=0.8 o'clock, protuberance is too approaching each other, guided wave effect is weak).On the other hand, according to the curve 27A of Figure 23, in secondary light is drawn, ratio P is set in to 0.5～0.98 scope centered by 0.9, can further improve light ejection efficiency.Therefore, comprise in total light ejection efficiency for the first time, for the second time, preferably ratio P is set in to 0.4～0.98 scope.

So, in the present embodiment, make ratio P stagger 0.5, can access the light ejection efficiency higher than the first embodiment.In addition, the same with the first embodiment, except the distribution of the light intensity that can avoid causing because of orientation and look unbalance, the effect also having is, can realize the significantly raising of light ejection efficiency, and suppresses mirroring of extraneous picture etc.

(the 3rd embodiment)

Based on Figure 22 (b), the 3rd embodiment is described.Also having the 3rd embodiment is the discrepancy in elevation condition difference of surface structure 13, and other structures are identical with first, second embodiment, for its explanation of common incomplete structure.

The 3rd embodiment is two tiny area δ that make the adjacency of the surface structure in first, second embodiment ₁, δ ₂between the amount of the discrepancy in elevation be random situation.As reaching random method, in Figure 13 (a), the surface of transparency carrier 5 is seamlessly divided into the wide w gridiron pattern of (being called boundary width) (foursquare tiny area δ), based on random function, for single reference field, setting-d at random in lattice one by one _m/ 2～d _mheight (or degree of depth) arbitrarily between/2.As single reference field, be the existing tiny area δ in the extreme higher position face existing and parallel with the surface of transparency carrier 5 with the centre of the existing tiny area δ of extreme lower position in the direction of the surperficial face normal parallel with transparency carrier 5.D _mwhat be tiny area δ in extreme higher position and the tiny area δ in minimum in the position of short transverse is poor.

Figure 22 (b) means the key diagram of light ejection efficiency of the surface structure of present embodiment, is illustrated in the refractive index n of transparency carrier 5 ₁=1.457, the refractive index n of air 6 ₀=1.0, light wavelength λ=0.635 μ m and transverse axis are made as boundary width (width of tiny area δ) w and the maximum discrepancy in elevation d of surface structure _mthe ejection efficiency of light for the first time η during=1.4,0.9,0.7,0.3 μ m ₁light ejection efficiency η for the second time ₂.From situation about calculating, as the randomness of the high residual quantity apart from reference field, with the following random condition (probability of occurrence is respectively 25% condition) of selecting, select at random respectively: d _mduring=1.4 μ m, with-0.7 μ m～0.7 μ m, by 0.467 μ m step, carry out the random selection of 4 kinds of discrepancy in elevation; d _mduring=0.9 μ m, with-0.45 μ m～0.45 μ m, by the 0.3 μ m ladder utmost point, carry out the random selection of 4 kinds of discrepancy in elevation; d _mduring=0.7 μ m, with-0.35 μ m～0.35 μ m, by 0.233 μ m step, carry out the random selection of 4 kinds of discrepancy in elevation; d _mduring=0.3 μ m, with-0.15 μ m～0.15 μ m, by 0.1 μ m step, carry out the random selection of 4 kinds of discrepancy in elevation.Also have, the probability of occurrence of each step does not need equalization, for example, can reduce the probability of occurrence of the step of low (dark) position yet, can strengthen the probability of occurrence of the step of high (shallow) position yet.

Curve 6i, 6I are respectively d _mduring=1.4 μ m for the first time with secondary smooth ejection efficiency, curve 6h, 6H are respectively d _mduring=0.9 μ m for the first time with secondary smooth ejection efficiency, curve 6g, 6G are respectively d _mduring=0.7 μ m for the first time with secondary smooth ejection efficiency, curve 6f, 6F are respectively d _mduring=0.3 μ m for the first time with secondary smooth ejection efficiency.Same with the first embodiment, primary smooth ejection efficiency all reaches greatly when boundary width w is 0.2～2 μ m, if reduce or increase w, is gradually to 0.27 (so-called value of being given with (formula 3), light ejection efficiency when surface is minute surface).Secondary smooth ejection efficiency is when the μ m of w≤0.20, along with w diminishes and to 0.00 convergence, although do not present in figure, if make w larger than 8 μ m, is gradually to 0.Therefore, the scope of boundary width w need to be value more than 0.2 μ m, in addition as the first embodiment Figure 14, Figure 15 discussed, according to the relation of field angle interdependence and preferably below 1.5 μ m.In Figure 22 (b), at d _munder the condition of=0.7 μ m, boundary width w=0.6 μ m, calculate for the first time, secondary smooth ejection efficiency (η ₁, η ₂) be 0.331,0.141.So d _mthe resulting characteristic of=0.7 μ m and resulting characteristic in the first embodiment (curve 5A) are compared with resulting characteristic (curve 6B, 6C) in the second embodiment, and secondary smooth ejection efficiency improves.This be considered to due to, the front end of protuberance is irregular, the randomness of pattern strengthens, the randomness in the propagation orientation of the light reflecting at surface structure also strengthens, catoptrical diffusivity improves, in secondary light is drawn, light also can be to approach primary state (state of the light intensity of Omnibearing even) incident.

Also have, in the scope of w>=0.4 μ m, with d _m=0.7 μ m compares, d _mthe primary deterioration in characteristics of=0.30 μ m, so d _mbe preferably d _m>=0.2～0.3 μ m (this scope is identical with the first embodiment).In addition, d _min the situation of=1.40 μ m, in the scope of w>=1.0 μ m, with d _m=0.7 μ m compares, and primary characteristic is slightly improved, if but d _mexcessive,, except processing difficulties, under the condition of w>=1.5 μ m, field angle characteristic is deteriorated (with reference to Figure 14,15) also, and therefore 1.40 μ m can be described as d _mupper limit target.The scope of these scopes and the first embodiment (λ/(n ₁-n ₀)>=d _m>=λ/6 (n ₁-n ₀) identical.

Like this, the 3rd embodiment, by making the amount randomization of the discrepancy in elevation, can access the light ejection efficiency higher than first, second embodiment.In addition, the same with the first embodiment, except not can because of orientation cause the distribution of light intensity and look unbalance, also there is the effect that suppresses that extraneous picture is mirrored etc.

Also have, as the randomized condition of the amount that makes the discrepancy in elevation, think and have following two kinds of situations: get from 0 to the high residual quantity d of maximum (1) _mwhole values; (2) comprise 0 and maximum high residual quantity d _minterior and get the arbitrary value within the more than three grades discrepancy in elevation.Wherein as the example of (2), if consider, get 0, d _m/ 3, d _m* 2/3, d _mthe situation of these 4 kinds of discrepancy in elevation, the mould of using for this surface structure being formed to the shape transferred thereon of sheet surface, can be through double exposure, etching work procedure (for the first time: use boundary width w ₁mask pattern, through exposure, carry out dark d _m/ 3 etching, for the second time: mask is become to boundary width w ₂mask pattern, through exposure, carry out dark d _m* 2/3 etching) make.At this moment, in order to make the frequency of occurrences of discontinuous boundary line reach maximum, with w ₂=w ₁for condition.

In addition, if consider, get 0, d _m/ 6, d _m* 2/6, d _m* 3/6, d _m* 4/6, d _m* 5/6, d _mthe situation of these 7 kinds of height (discrepancy in elevation), the mould of using for such surface structure being formed to the shape transferred thereon of sheet surface, can be through three exposures, etching work procedure (for the first time: use boundary width w ₁mask pattern, through exposure, carry out dark d _m/ 6 etching, for the second time: mask is become to boundary width w ₂mask pattern, through exposure, carry out dark d _m* 2/6 etching, for the third time: mask is become to boundary width w ₃mask pattern, through exposure, carry out dark d _m* 3/6 etching) make.At this moment, in order to make the frequency of occurrences of discontinuous boundary line reach maximum, with w ₁=w ₂=w ₃for condition.

(the 4th embodiment)

Based on Figure 24, the 4th embodiment is described.Also having the 4th embodiment is that the pattern of surface structure is different from the first embodiment, and other structures are identical with the first embodiment, for its explanation of common incomplete structure.

Figure 24 represents to the process determining till the pattern of surface structure of the 4th embodiment.Figure 24 (a) becomes wide w by the surface segmentation of transparency carrier 5 ₁gridiron pattern (foursquare tiny area α), make ratio that lattice are one by one black or white each 50% and distribute randomly black and white figure, the example shown in figure is w ₁situation (the w of=1 μ m ₁optimum value have less situation, but because as figure be difficult to watch, so describe by this value).Being assigned as black tiny area α is tiny area α ₁, being assigned as white tiny area α is tiny area α ₂.

Figure 24 (b) becomes w by the surface segmentation of transparency carrier 5 ₁the big or small width w of integral multiple ₂gridiron pattern (foursquare tiny area β) and lattice be one by one that black ratio is P ₂, and white ratio be 1-P ₂and P ₂=0.5 and distribute randomly white and black figure, the example shown in figure is w ₂the situation of=2 μ m.Being assigned as black tiny area β is tiny area β ₁, being assigned as white tiny area β is tiny area β ₂.

To be the pattern that makes Figure 24 (a), Figure 24 (b) in the mode of gridiron pattern alignment overlapping and follow the pattern of following law generation for Figure 24 (c): black (α ₁) and black (β ₁) overlapping become white, white (α ₂) and white (β ₂) overlapping become white, white (α ₂) and black (β ₁) or black (α ₁) and white (β ₂) overlapping become black.Figure 24 (c) is as a result of with the pattern of Figure 24 (a) and generates rule and be equal to, and take blackly in protruding, and it is identical that the pattern that is recessed surface structure in vain with respect to this relativity ground is introduced with the first embodiment.

On the other hand, Figure 24 (d) becomes wide w by the surface segmentation of transparency carrier 5 ₁gridiron pattern (foursquare tiny area α) and lattice be one by one that black ratio is P ₁, and be that white ratio is 1-P ₁and the figure distributing randomly, the example shown in figure is w ₁=1 μ m, P ₁=0.1 situation.Same with Figure 24 (a), black is tiny area α ₁, be tiny area α in vain ₂.

To be the pattern that makes Figure 24 (d), Figure 24 (b) in the mode of gridiron pattern alignment overlapping and according to the pattern of following law generation for Figure 24 (e): black (α ₁) and black (β ₁) overlapping become white, white (α ₂) and white (β ₂) overlapping become white, white (α ₂) and black (β ₁) or black (α ₁) and white (β ₂) overlapping become black.Figure 24 (e) has the feature similar to the pattern of Figure 24 (c): if black, white area ratio is 1: 1; The minimum dimension of black mark, white marker is identical etc., but the low this point of the appearance ratio of minimum dimension is different.The ratio of final B&W (concavo-convex area ratio) is by ratio P ₁, P ₂determine, black ratio P (protruding ratio) is by P=P ₁+ P ₂-2P ₁p ₂provide.

In Figure 23, at projecting height d=0.7 μ m, the w of the convex portion of surface structure ₁=0.2 μ m, w ₂=1 μ m, P ₁under=0.1 condition, by form that protruding ratio P is made as that transverse axis calculated for the first time, secondary smooth ejection efficiency (η ₁, η ₂) characteristic as curve 27b, 27B, carry out note.

According to the curve 27b of Figure 23, no matter the concavo-convex distribution of the pattern different from the first embodiment how, in light is drawn for the first time, by the ratio P of the concavo-convex area ratio of domination being set in to 0.4～0.8 scope centered by 0.6, can both further improve light ejection efficiency.On the other hand, according to curve 27B, in light is drawn for the second time, by ratio P being set in to 0.5～0.9 scope (because be set as P ₁=0.1, so curve 27b, 27B can not draw below 0.1, more than 0.9), can further improve light ejection efficiency.Therefore, same with the first embodiment, by combination ratio P ₁, P ₂and the protruding ratio P of final formation is set in to 0.5～0.98 scope, can improve the total light ejection efficiency comprising for the first time, for the second time.Also have, curve 27c, the 27C of Figure 23 are w ₁=0.1 μ m, P ₁under=0.1 condition for the first time, the characteristic of secondary smooth ejection efficiency, curve 27d, 27D are w ₁=0.1 μ m, P ₁under=0.2 condition for the first time, the characteristic of secondary smooth ejection efficiency.Because make w ₁less than 0.2 μ m, efficiency can be greatly deteriorated, so need w ₁it is value more than 0.2 μ m.In addition, w ₁higher limit as the first embodiment Figure 14, Figure 15 discussed, according to the relation of field angle interdependence, be preferably below 1.5 μ m.

The 4th embodiment is to make the formation condition of surface structure have some changes with respect to the first embodiment, because condition is different, light ejection efficiency has some deteriorated than the first embodiment, but still can realize than the large light ejection efficiency of existing light-emitting device shown in Fig. 1, Fig. 3 (a), same with the first embodiment, except the distribution of the light intensity that can avoid causing because of orientation and look unbalance, can also realize the significantly raising of light ejection efficiency, also there is the effect of mirroring of the picture that suppresses extraneous etc.Other the 4th embodiment is compared with the first embodiment, loose about the restriction condition of the shape of surface structure, therefore can obtain wide in range error span, in the advantage that has of handling ease degree.For example, under the condition of the first embodiment, because the interval of recess and recess or protuberance and protuberance approaches, so processing fine concaveconvex shape has any problem, but in the 4th embodiment, because the appearance ratio of fine recess or protuberance low (with reference to (c) of Figure 24 and (e)), so the interval of recess and recess or protuberance and protuberance is expanded effectively, the obstacle step-down of the difficulty of processing.Also have, in the second embodiment, apply the 4th embodiment, certainly also can access the effect same with the second embodiment.

(the 5th embodiment)

The combination of the 4th embodiment and the 3rd embodiment is exactly the 5th embodiment.In the present embodiment, in order to make the setting in region comprehensible, with each region of colouring discrimination, describe.In the 5th embodiment, first, the surface segmentation of transparency carrier 5 is become to wide w ₁gridiron pattern (foursquare tiny area α), making lattice is one by one that black ratio is P ₁, be that white ratio is 1-P ₁and be distributed into randomly black and white, for being distributed into white region (tiny area α ₂) by the degree of depth, be d ₁(> 0) engraves (enchase) with the method for etching etc.Being distributed in addition black region is tiny area α ₁.

Secondly, the surface segmentation of transparency carrier 5 is become to wide w ₂gridiron pattern (foursquare tiny area β), making lattice is one by one that blue ratio is P ₂, be that red ratio is 1-P ₂and distribute randomly Lan Hehong, for being distributed into red region (tiny area β ₂) by the degree of depth, be d ₂(> 0) engraves (enchase) with the method for etching etc.Being distributed into blue region is tiny area β ₁.Width w wherein ₂width w ₁integral multiple (w most preferably ₂=w ₁), make boundary line alignment and overlapping each gridiron pattern.

So, the face of the part that the Bai Yuhong of usining is overlapping is during as reference field, and with respect to this reference field, black with blue overlapping its height can reach d ₁+ d ₂, overlapping its height of Bai Yulan can reach d ₂, or black and red overlapping its height can reach d ₁.Therefore, the discrepancy in elevation can be got from 0 to d at random ₁+ d ₂between 4 kinds of values (0, d ₁, d ₂, d ₁+ d ₂), therefore can access the effect same with the 3rd embodiment.

And, if be set as d ₁=d _m* 1/3, d ₂=d _m* 2/3, with fine structure, make the wide w of difficulty ₁pattern just can make the degree of depth shoal, therefore on the easness of processing, there is advantage.D ₁=d _m* 1/3, d ₂=d _m* 2/3 o'clock, ratio P ₂corresponding (in fact at ratio P by the dark side of the amplitude of engraving with it ₂one side is 2 flexible strategy, ratio P ₁one side is relevant with mean depth under 1 flexible strategy), therefore with determine concavo-convex area ratio, be the ratio P of the 4th embodiment of the average level of the degree of depth ₂there is similar meaning.On the other hand, ratio P ₁with fine structure (width w ₁) appearance ratio relevant, therefore with the ratio P of the 4th embodiment ₁there is similar meaning.

Also have, in the above embodiments, combined two kinds of exposures, etching work procedure, if but combine 3 kinds of exposures, etching work procedure, can from 8 kinds of values, obtain random height.This situation adds following operation in 2 above-mentioned etching work procedures.That is, the surface segmentation of transparency carrier 5 is become to wide w ₃gridiron pattern (foursquare tiny area γ), making lattice is one by one that green ratio is P ₃, be that yellow ratio is 1-P ₃and distribute randomly green and yellow, for being distributed into yellow region (tiny area γ ₂) by the degree of depth, be d ₃engrave with the method for etching etc. (> 0).Being distributed in addition green region is tiny area γ ₁.Width w wherein ₃width w ₂integral multiple (w most preferably ₃=w ₂), make boundary line alignment and overlapping each gridiron pattern.

So, using the face of white and red and yellow overlapping part, during as reference field, with respect to this reference field, black and blue and green overlapping its highly can reach d ₁+ d ₂+ d ₃, white and blue and green overlapping its height can reach d ₂+ d ₃, or overlapping its height of black and Lan Hehuang can reach d ₁+ d ₂, black and red and green overlapping its height can reach d ₁+ d ₃, black and red and yellow overlapping its height can reach d ₁, white and blue and yellow overlapping its height can reach d ₂, white and red and green overlapping its height can reach d ₃.Therefore, the discrepancy in elevation can be got from 0 to d at random ₁+ d ₂+ d ₃between 8 kinds of values (0, d ₁, d ₂, d ₃, d ₁+ d ₂, d ₂+ d ₃, d ₃+ d ₁, d ₁+ d ₂+ d ₃), therefore can access the effect same with the 3rd embodiment.

And, if be set as d ₁=d _m* 1/6, d ₂=d _m* 2/6, d ₃=d _m* 3/6, with fine structure, make the wide w of difficulty ₁and w ₂pattern just can make the degree of depth shoal, therefore on the easness of processing, there is advantage.At d ₁=d _m* 1/6, d ₂=d _m* 2/6, d ₃=d _m* 3/6 o'clock, ratio P ₂and P ₃with to be engraved the dark side of amplitude corresponding (in fact at ratio P ₃one side is 3 flexible strategy, ratio P ₂one side is 2 flexible strategy, ratio P ₁one side is relevant with mean depth under 1 flexible strategy), therefore, P ₂, P ₃with determine concavo-convex area ratio, determine the ratio P of the 4th embodiment of the average level of the degree of depth ₂there is similar meaning.On the other hand, because ratio P ₁with fine structure (width w ₁) appearance ratio relevant, so with the ratio P of the 4th embodiment ₁there is similar meaning.

(the 6th embodiment)

Based on Figure 12, the 6th embodiment is described.Also have, the 6th embodiment only has the pattern of surface structure 13 different from the first embodiment, and other structures are all identical with the first embodiment, about its explanation of common incomplete structure.

The 6th embodiment is two tiny area δ that make the adjacency of the surface structure in the first embodiment ₁, δ ₂the embodiment being formed by phase shifter.Phase shifter is for example formed by the different multilayer film of refractive index.That is, utilize the multipath reflection of multilayer film, can adjust the phase place of transmitted light; By changing the structure (thickness and the number of plies) of multilayer film, can form at random the region of 180 degree and the region of 0 degree.In addition, with polarizer, change the polarisation of light that sees through two regions, also can obtain same effect.At this moment, the polarized light of the 180 corresponding transmitted lights in degree region is P polarized light or right-circularly polarized light, the polarized light of the 0 corresponding transmitted light in degree region is S polarized light or left circularly polarized light, if such polarizer is used orientation to have 1/2 different wavelength plate of 90 degree, also can realize.Also have, the sag and swell at the first embodiment interface such, that refractive index there are differences, because the phase place of transmitted light also changes at concavo-convex, just can be described as a kind of mode of phase shifter.

The incident angle-dependent of the transmissivity t of the surface structure 13 of present embodiment and light ejection efficiency show to some extent in Fig. 9, Figure 19 (b) (curve 5d, 5D), and primary smooth ejection efficiency is also that more than 0.4 μ m the scope below 1 μ m can surpass the light ejection efficiency while being minute surface on surface at w.In Figure 19 (b), the result that makes phase differential reach 90 degree is also shown, for the first time, secondary smooth ejection efficiency represents by curve 5d ', 5D ' respectively.Since all deteriorated than the light ejection efficiency (curve 5d, 5D) of phase differential 180 degree, so the optimum value of known phase differential is 180.

Like this, the 6th embodiment forms surface structure 13 by phase shifter, can access the light ejection efficiency higher than conventional example.In addition, same with the first embodiment, except the distribution of the light intensity that can avoid causing because of orientation and look unbalance, also there is the effect of mirroring of the picture that suppresses extraneous etc.

(the 7th embodiment)

Based on Figure 25, the 7th embodiment is described.Also have, the 7th embodiment only has the pattern of surface structure 13 different from the first embodiment, and other structures are all identical with the first embodiment, about its explanation of common incomplete structure.

Figure 25 (a) represents the pattern figure of the first surface structure 23 of present embodiment.As shown in Figure 25 (a), in surface structure 23, the surface segmentation of transparency carrier 5 is become to make the equilateral triangle (tiny area δ) that length is on one side w, make tiny area δ or protruding ((the tiny area δ of the 23a in figure one by one ₁), the figure of grey) or recessed ((the tiny area δ of the 23b in figure ₂), white figure) ratio each 50%, distribute randomly protruding and recessed.W is below 2.25 μ m.

On the other hand, Figure 25 (b) represents the pattern figure of the second surface structure 33 in present embodiment.The surface segmentation of transparency carrier 5 is become to make the regular hexagon (tiny area δ) that length is on one side w, and making figure is one by one protruding ((the tiny area δ of the 33a in figure ₁), the figure of grey) or be recessed ((the tiny area δ of the 23b in figure ₂), white figure) ratio each 50%, distribute randomly protruding and recessed.W is below 0.93 μ m.

Also have, if usually performance, the size of figure be take the condition of the following is: with the maximum diameter of the circle of this figure inscribe more than 0.2 μ m, below 1.5 μ m.

The 7th embodiment only has the shape of pattern of surface structure 23,33 different from the first embodiment, and action principle is identical with the first embodiment, and can access same effect.In addition, it is not limited to equilateral triangle and regular hexagon, if can carry out face with identical figure gapless, cuts apart, and polygon can arbitrarily.

Also have, in the first to the 7th embodiment, the surface structure 13,23,33 of actual processome is not square and equilateral triangle strictly speaking, but the part at angle becomes this deflection of angular deformation of the tiny area that the tiny area of circle or angle change circle is adjacent, even in this case, certainly can deterioration in characteristics yet, can obtain same effect.In addition, second, to the 6th embodiment, apply the 7th embodiment, also can access with second to the same effect of the 6th embodiment.

(the 8th embodiment)

The 8th embodiment is described.Also have, the 8th embodiment only has surface structure different from the first embodiment, and other structures are identical with the first embodiment, about its explanation of common incomplete structure.

Figure 26 (a) is the sectional view of the light-emitting device of present embodiment.Figure 26 (b) is the vertical view of the light-emitting device of present embodiment.The light-emitting device of present embodiment has: substrate 101, electrode 102, luminescent layer 103, transparency electrode 104, transparency carrier 105 and be located at the surface structure 13 on transparency carrier 105.The light that is formed present embodiment by transparency carrier 105 and surface structure 13 is drawn thin slice.

In the present embodiment, effective refractive index is n _amicrobody A and effective refractive index be n _bmicrobody B, by shakedown very close to each other, established that to be configured in effective refractive index be n _btransparency carrier 105 on.Microbody A and microbody B thickness are that the width of d, upper surface is w.Then, as shown in Figure 26 (b), be configured in randomly on transparency carrier 105.In Figure 26, microbody A and microbody B are cube, but can be also rectangular parallelepiped and multiaspect scapus etc., as long as have the shape that can lay on the surface of transparency carrier 105.In addition, microbody A and microbody B also can have mutually different shape.

Mode of the present invention, is in having the small concavo-convex surface structure of the first embodiment, have that protuberance consists of microbody B and recess by the structure of microbody A landfill.That is, the microbody A of present embodiment, is equivalent to air or the medium of the recess of the first embodiment.In addition, the microbody B of present embodiment, is equivalent to the protuberance on the transparency carrier surface of the first embodiment.Therefore, if make the refractive index n of the air (or medium) in the first embodiment ₀refractive index n for microbody A _a, the refractive index n of transparency carrier _brefractive index n for microbody B _b, in the present embodiment, also can be suitable for the analysis result illustrating in the first embodiment.That is by inscribe greatest circle diameter, be, microbody A below the above 1.5 μ m of 0.2 μ m and microbody B be the surface that the mode of more than 40% ratio below 98% is laid on transparency carrier randomly according to making microbody A.Thus, as described in detail in the first embodiment, visible light can drawn from the face towards opposite side of a side under critical angle.In addition, the thickness at microbody A is made as d, effective refractive index is made as n _a, microbody B thickness be made as d, effective refractive index is made as n _b, λ be the luminophor that makes it to use adjacently send light wavelength time, with λ/6 (n _b-n _a) < d < λ/(n _b-n _a) mode set d, can significantly improve light ejection efficiency thus.

In the present embodiment, because can make surface structure smooth, so the surface configuration concavo-convex like this with the first embodiment compared, dust and dirt can be alleviated to the adhering to of surface, the deteriorated of light ejection efficiency can be prevented.

Then,, as an example of above-mentioned microbody A and microbody B, the example that uses nano particle to form microbody A and microbody B is described.

Figure 27 (a) is the sectional view of light-emitting device.Figure 27 (b) is that Figure 27 (a) is along the sectional view of A face.As shown in 27 (a), configuration on transparency carrier 105: nano particle (solid nano particle) b of the nano particle a of hollow and the non-hollow of same outer diameter d.Below, be referred to as hollow nano particle a and solid nano particle b.

Hollow nano particle a comprises: hollow bulb 307 and to surround the set housing department 308 of mode of hollow bulb 307.Hollow bulb 307 be cavity, hollow bulb 307 such as be full of the gases such as air and nitrogen also can, hollow bulb 307 is that vacuum also can.

On the other hand, solid nano particle b has the structure being filled.The external diameter of hollow nano particle a and solid nano particle b is d, and the diameter of hollow bulb 307 is the inner diameter d of housing department 308 namely '.Hollow nano particle a and solid nano particle b, can be used hollow silica particle and silicon dioxide granule.Hollow silica particle and the silicon dioxide granule of profile of various sizes with the scope more than 0.2 μ m, below 1.5 μ m is on sale on market, can obtain.In addition, can obtain the hollow silica particle of the hollow space with various sizes.In addition, can also use following hollow nano particle and solid nano particle: used the Hollow Latex Particles of styrene, cross-linked styrene, modified phenylethylene/butadiene etc., and the solid nano particle of PMMA particle etc. etc.

The refractive index of the housing department 309 of hollow nano particle a and the refractive index of solid nano particle b, with the refractive index of transparency carrier 305 about equally.

These nano particles are buried by bonding agent 108 and are fixed on transparency carrier 105, and this bonding agent 108 has and the refractive index of transparency carrier 105 refractive index about equally.In addition, the upper end of housing department 309 contacts and configures with air layer 106.So, microbody A just comprises the external structure that consists of the housing department 309 of hollow nano particle a and bonding agent 108 and the internal structure consisting of the hollow bulb 307 of hollow nano particle a, and has the mutually different duplex of the refractive index of making.

The cubical region of containing hollow nano particle a, can treat as the refractive index of homogeneous in actual effect.That is, the region 310a being illustrated by the broken lines that contains hollow nano particle a, can be considered as having effective refractive index n _amicrobody A.In addition, the region 310b being illustrated by the broken lines that contains solid nano particle b, can be considered as having effective refractive index n _bmicrobody B.At this, if the refractive index of bonding agent 308 is made as n _x, hollow bulb 307 refractive index be made as n ₀, refractive index n in actual effect _a, n _bby (formula 7) shown below and (formula 8), represented.That is the external structure that, the effective refractive index of microbody A consists of housing department 309 and the bonding agent 308 of hollow nano particle a and in-built refractive index and the volume ratio thereof consisting of hollow bulb 307 determine.

[formula 2]

$n_a=\frac{1-\frac{4}{3}\mathrm{\&pi;}{\left(\frac{d^{\&prime;}}{2}\right)}^3}{d^3}{n}_x+\frac{\frac{4}{3}\mathrm{\&pi;}{\left(\frac{d^{\&prime;}}{2}\right)}^3}{d^3}{n}_0$

[formula 3]

n _b＝n _x

Then,, in Figure 28, the analysis result of incident angle-dependent of the transmissivity t of the thin slice with the structure shown in Figure 27 is shown.Figure 28 is to be 0.1 μ m in (d-d ')/2, the analysis result when value of d is 0.3 μ m, 0.4 μ m, 0.6 μ m, 0.8 μ m, 1.0 μ m, 2.0 μ m, 4.0 μ m.In addition, the refractive index of the shell 309 of solid nano particle b, hollow nano particle a, and the refractive index of bonding agent 308 is n _x=1.457, the refractive index n of the hollow bulb 307 of hollow nano particle a ₀=1.0, wavelength is 635.As shown in Figure 28, even under the angle more than critical angle 43.3 degree, also can confirm the effect of drawing with very large light, can access boundary diffraction effect.

In addition, the light ejection efficiency η when d is 0.3 μ m, 0.4 μ m, 0.6 μ m, 0.8 μ m, 1.0 μ m, 2.0 μ m, 4.0 μ m shown in Figure 29.The known ejection efficiency of light for the first time reaches maximal value 0.32 near the μ m of d=0.6～2.0, can access and the equal light ejection efficiency roughly of the boundary diffraction structure shown in the first embodiment.In addition, light ejection efficiency diminishes in less than d=0.3 μ m for the second time.Known while being 0.1 μ m in (d-d ')/2, d at least need to be more than 0.3 μ m.

Then, in thin slice thering is the structure shown in Figure 27 shown in Figure 30, footpath ratio (d-d ')/d=0.1,0.3,0.5, the analysis result of light ejection efficiency when d=0.2 μ m, 0.3 μ m, 0.4 μ m, 0.6 μ m, 0.8 μ m, 1.0 μ m, 2.0 μ m, 4.0 μ m.As shown in Figure 30, footpath ratio is larger, and primary smooth ejection efficiency is less, particularly in ratio=0.5, footpath, during d < 0.6 μ m, primary smooth ejection efficiency almost approaches the value of minute surface, so the upper limit of footpath ratio can be considered 0.5.As can be known from the above results, need to be with respect to the volume of microbody A integral body and the shared volume ratio of hollow bulb is more than 1/16.In addition we know,, (d-d ')/d=0.1,, at d=0.2 μ m, also make light ejection efficiency improve at 0.3 o'clock.Accordingly, need to be more than 0.2 μ m as the value of d.

Also have, in the present embodiment, microbody A and microbody B configuration in the plane, be arranged in chessboard trellis shown in Figure 27 (b), but also can random alignment or make it to be arranged in closest packing structure.

In addition, in order to ensure randomness, after preferably hollow nano particle a and solid nano particle b being mixed, be dispersed in liquid phase and be coated on transparency carrier 105 after make it to be dried and make hollow nano particle a and solid nano particle b to arrange.Because hollow nano particle a and solid nano particle b are dispersed in liquid phase randomly, so the arrangement after coating can be also random.

In addition, as the method that makes hollow nano particle and solid nano particle random arrangement, can be also following method.That is, first, prepare to make to have the mixture that the hollow nano particle of polarity and solid nano particle have mixed with the ratio of regulation.Secondly, the surface of transparency carrier 105 is implemented to process, make it to become and the opposite polarity polarity that hollow nano particle and solid nano particle are implemented.Then, on this transparency carrier 105, be coated with aforesaid mixture, can realize at an easy rate random alignment thus.

By the particle of the means institute random arrangement by above, via the bonding agent with the refractive index same with transparency carrier, (for example the refractive index of transparency carrier is 1.457 o'clock, with acrylic resin adhesive material FA-125M) etc. fixing, can make thus light and draw thin slice.

Also have, in the present embodiment, arrangement be hollow and solid spherical object, but so long as make the different structure of effective refractive index, just can guarantee the phase differential of transmitted light, can access boundary diffraction effect.For example, also can make the solid nano particle of the mutually different same shape of refractive index mixedly arrange.In addition, as Figure 31 (a) with (b), making the diameter d of the hollow bulb (in the drawings not by the part of shadow representation) of hollow nano particle ' mutually different mix particles also can.In addition, as Figure 32 (a) with (b), the shape of nano particle is that cube and polyhedron also can.In addition, thereby also can at surperficial neighborhood, bubble be occurred or the crystal structure of surperficial neighborhood is changed change the method for refractive index etc. by substrate surface being carried out to Ear Mucosa Treated by He Ne Laser Irradiation, make thus effective refractive index different microbody A, B.

(other embodiment)

Above-mentioned embodiment is illustration of the present invention, and the present invention is not subject to the restriction of these examples.In the first to the 7th embodiment, the cross sectional shape vertical with the surface of the protuberance of surface structure is not limited to rectangle, can be also trapezoidal and cone shape, and the inclined-plane of protuberance can be also curve.

In addition, in the first to the 8th embodiment, when the thickness of transparency carrier 5 is large, the number of times increase that draw whenever light the outgoing position of light will be from the position deviation of luminous point S.In this case, in the structure after being distinguished by the pixel of 300 μ m left and right as the EL that display is used, light can be sneaked into adjacent pixel and be caused the deteriorated of image quality.Therefore as Figure 33 (a) as shown in, consider following structure: the transparency carrier 5 that is formed with surface structure 13 is formed to be as thin as the mode of several μ m left and right, and press from both sides every air layer and by protective substrate 14 coverings of 0.2mm～0.5mm left and right thereon.Can there is not total reflection in surperficial 14a, back side 14b at protective substrate, but need AR (antireflection) coating.At this moment, also can on surface structure 13, with the low-refractions such as aerogel and transparent material, replace air layer, at this moment because be integrative-structure, so high as the stability of device.

In addition, in the first to the 8th embodiment, only on a face, be formed with surface structure 13, but also can form on the two sides of transparency carrier 5 same structure.Also can between surface structure 13 and luminous point S, configure general diffraction grating 13 ' in addition.At this moment the structure of considering, as shown in Figure 33 (b), makes transparency carrier 5 form film-form, and its surface forms surface structure 13, and its back side forms the surface structure 13 of diffraction grating 13 ' and other specifications ", on luminous side, via adhesive linkage 21, make it bonding.The refractive index of transparency carrier 5 is little, with the refringence of luminescent layer 3 be 0.1 when above, if select the material of adhesive linkage 21, make it than the refractive index of luminescent layer 3 only little 0.1 or little more, can there is total reflection in the boundary face at adhesive linkage 21 and luminescent layer 3 hardly, and the total reflection occurring at the plane of refraction between adhesive linkage 21 and transparency carrier 5 and the plane of refraction between transparency carrier 5 and air 6, respectively can be by surface structure 13 " (or diffraction grating 13 ') and surface structure 13 avoided.Also have diffraction grating 13 ' and surface structure 13 " the degree of depth of recess or the highly preferred condition of protuberance be at the transmitted light of recess with at the transmitted light of protuberance, π phase differential can occur, but can be also the recessed degree of depth or the protruding less condition of height.

Also have as a reference, also figure 34 illustrates the pattern figure that surface structure is grid style (gridiron pattern shape).In Figure 34, in surface structure, the surface segmentation of transparency carrier 5 is become to make the square that length is on one side w, and the square 13a of grey and white square 13b form gridiron pattern pattern, and grey is protruding, relatively white is recessed shape.

The figure of the incident angle-dependent of the transmissivity t of the surface structure shown in Figure 34 when Figure 35 means discrepancy in elevation d=0.70 μ m concavo-convex under the condition identical with Figure 19 (a), light in the interior light quantity 1 of transparency carrier 5 incides surface structure and has for the first time the light how to measure to shine air 6 sides with angle θ (with the angle of plane of refraction normal), take width w as parameter (w=0.1,0.2,0.4,1.0,2.0,4.0 μ m), illustrated.If Figure 35 is compared known with the Figure 16 (a) with the characteristic of random pattern, remove the curve in w=0.1,0.2 μ m (the so-called region that the nanometer structure of diffraction light does not occur), all there is very tiny fluctuating.This represents, because the diffraction that gridiron pattern pattern forms makes diffraction light occur or disappear in air layer side, so distribute to some extent according to orientation different light intensity degree, is the intrinsic problem of periodic pattern.

Present the surface structure that presents swallow-grid (part by four limits of wide w is a recessed side) shown in the surface structure of this gridiron pattern shape and Fig. 4 (b), its for the first time with secondary smooth ejection efficiency note (d=0.70 μ m, is respectively curve 5e, 5f, 5E, 5F) in Figure 19 (b).Why large the secondary smooth ejection efficiency of swallow-grid pattern is, and the phenomenon of introducing with Figure 23 is identical, is because form protruding ratio P=0.75 in swallow-grid pattern.Compare with the characteristic of random pattern, gridiron pattern pattern, swallow-grid pattern all illustrate the characteristic rising and falling along with the variation of w, and this is also the intrinsic problem of periodic pattern, the relation that is distributed with of the light intensity causing with orientation.

In Figure 36 (a), (b), note is from the primary analysis result of drawing the field angle interdependence of light of the surface structure institute outgoing of gridiron pattern pattern.Discrepancy in elevation d=0.70 μ m, boundary width w=0.5 μ m, Figure 36 (a) is the condition of λ=0.450 μ m, Figure 36 (b) is the condition of λ=0.635 μ m.Solid line (the longitude orientation of 0 degree, 90 degree), dotted line (the longitude orientation of 45 degree, 135 degree) are all large with respect to the change of drift angle, and both differences are also large, knownly because wavelength causes shape, change a lot.Distribution and the look unbalance generation of the light intensity causing because of orientation, this is the same with the light-emitting device described in patent documentation 1, is the fatal defect in periodic pattern.These problems can overcome completely in the first to the 8th embodiment.

Boundary diffraction effect occurs when above the discontinuous part of phase place that makes light is separated by a certain interval, therefore, in order to make this effect maximization, need in limited area, make the appearance ratio maximization of the discontinuous part of phase place.If plane of refraction is cut apart by countless tiny areas, the boundary between tiny area makes phase place become discontinuous, by two conditions, can make the aforesaid ratio maximization that occurs.First condition is that the area of each tiny area is unified as far as possible; Second condition is between adjacent tiny area, also to have phase differential.That is, if there are other more large-area regions within tiny area, cut apart a side of this large area, the discontinuous boundary of phase place increases.On the contrary, if there are other more regions of small size within tiny area, there are other more large-area regions in this, cuts apart a side of this large area, and the discontinuous boundary of phase place increases.As its extended line, the area of each tiny area is unified as far as possible, at least to include in respect to certain benchmark area be the scope (maximum diameter of a circle is the scope of 0.7～1.3 times with respect to the diameter as benchmark with the circle of tiny area inscribe) of 0.5～1.5 times to the area of each tiny area, and this will make the appearance ratio maximization of the boundary line between tiny area.The first to the 8th embodiment is followed this condition.Allow in addition the maximization of cutting apart for tiny area, if phase place is unified between adjacent tiny area, effect is still weak.Therefore between adjacent tiny area, also need dephased existence, need the distribution of random phase place, the 4th and the 5th embodiment etc. is followed this condition.That is, the light-emitting device of above-mentioned embodiment, is not the such effect from antireflection of light-emitting device of utilizing described in patent documentation 2, but utilizes the raising that makes the effect of boundary diffraction effect maximization realize ejection efficiency.

Also have, the first surface configuration to the 7th embodiment is different from surface state or the surface state shown in the light-emitting device described in patent documentation 2 of ground glass and rough surface etc.In the first, the 4th and the 7th embodiment, surface segmentation is become to the gridiron pattern (or polygonal lattice) of wide w, for lattice one by one, protruding and recessed ratio with 1: 1 is distributed, the shape that has the such yardstick of intrinsic width w and intrinsic tiny area in this pattern, the ratio of the total area of protuberance and the total area of recess also remains the relation of 1: 1.With respect to this, the surface state of ground glass and rough surface etc. does not exist the shape of intrinsic width w and tiny area unsetting, and the relation that the ratio of the total area of protuberance and the total area of recess neither 1: 1.In the second embodiment, although protruding and recessed ratio departs from 50%, the ratio of the total area of recess and the total area of protuberance departs from 1: 1, still has intrinsic width w, the total area of recess and the total area of protuberance are still set value, have drawn a clear boundary line with the pattern of completely random.In the 3rd and the 5th embodiment, also have intrinsic width w, each discrepancy in elevation of the gridiron pattern being defined by this width w (or polygonal lattice) is different.So, the surface configuration in above-mentioned embodiment is not the pattern of completely random, can be described as the random pattern along certain rule.

Investigate a little different from the pattern of completely random.As shown in Figure 37 (a), the card 17 of 8 wide w of random alignment on the platform 16 of wide 4w.That is, the total area of 8 cards 17 be platform 16 area 1/2.But card 17 does not overflow platform 16.Figure 37 (b) allows the overlapping arrangement of card 17.Figure 37 (c) does not allow the overlapping arrangement of card 17.In Figure 37 (b), by card 17 underlapped amounts, the area summation that makes card is than long-pending 1/2 little of table top.If Area Ratio departs from from certain ratio, light ejection efficiency is deteriorated, and this was annotated by curve 27a, the 27b of Figure 23.In Figure 37 (c), although maintaining Area Ratio 1/2, between card, there is the small interval j less than w, this in Figure 37 (b) too.Small gap j occurs, if its frequency is large, j can be considered as to new boundary width, and as shown in Figure 22, under the condition of j < 0.2 μ m, light ejection efficiency is greatly deteriorated.In addition, as shown in figure 23, the ratio P of small sag and swell ₁increase and (press the order of curve 27a, 27c, 27d, w ₁the ratio P of the structure of=0.1 μ m ₁be increased to 0.0,0.1,0.2), even total protruding ratio identical, for the first time, secondary smooth ejection efficiency is also all deteriorated.So just the pattern of completely random just can not become the condition that makes light ejection efficiency maximum.

The generating principle of the random pattern adopting in above-mentioned embodiment is different from Figure 37's.In the above-described embodiment, Area Ratio is retained as a certain ratio, and the little yardstick of slight gap j proportional width w can not occur.So, the surface configuration of above-mentioned embodiment is not random pattern completely, can be described as along for making the regular random pattern of light ejection efficiency maximization.

In addition, the first phenomenon causing to the surface configuration of the 8th embodiment is one of diffraction phenomena.As shown in Figure 5, in diffraction phenomena, the light that refraction hypothetically occurs with respect to making the smooth reference field of surface configuration equalization is made as to 0 diffraction light (not showing during total reflection), the diffraction light of high order can occurs usining the orientation that moved under the benchmark of this light as orientation.In the such random surface profile of the application, the propagation orientation of the diffraction light beyond 0 time is random.With respect to this, can there is not diffraction phenomena in ground glass and rough surface, but one of refraction effect is to be only also random in the orientation random and that make to reflect, orientation of its face normal of concavo-convex plane of refraction.If form the surface configuration of first to seven embodiment and have an X-rayed the clear-cut of the picture of opposition side visible on parallel flat.This be due to, among the light of surface configuration diffraction dissociation, certainly exist diffraction light 0 time, this light is maintained the profile of the picture of opposition side.With respect to this, there is not the light that is equivalent to 0 diffraction light in ground glass and rough surface, if having an X-rayed the soft edge of the picture of opposition side.In patent documentation 2, only under surperficial thrust effect, make the performance of light " by directly emitting in air ", there is no the such performance of diffraction, if follow snell law (rule of refraction), can explain " directly " this word, its meaning can be interpreted as and belong to the kind that ground glass is identical with rough surface, can say with the present application and distinguish to some extent.

Attach, the disclosed technology of patent documentation 2 is characterised in that, on transparent insulation substrate, configure to completely random a plurality of transparent thrusts, as the application, make protuberance and recess as the more than one aggregate of the tiny area of same shape, and make protuberance and recess exist ratio to become the such feature of specific ratio not record also not hint.For example in the first embodiment, the structure that recess and protuberance have been replaced or the structure that the height of tiny area and the degree of depth have been replaced can be become to the structure roughly the same with structure originally, but the light-emitting device described in patent documentation 2 is not reached.By the feature of so exemplary embodiment, the present inventors have found that the significant light playing draws effect first, and in patent documentation 2, do not describe the so significant effect of above-mentioned embodiment.In the light-emitting device described in patent documentation 2, with in unit area 5000～10 ⁶individual/mm ²quantity meter, the thrust of wide 0.4～20 μ m is provided by random arrangement fully, say in form, a part for the light-emitting device of above-mentioned embodiment becomes form contained in this light-emitting device, but the relation of the shape of thrust and the part beyond it and the relation that has ratio, exist in addition the effect that this relation plays at first also not record and hint, in addition, above-mentioned in fact embodiment and be not included in the disclosed technology of patent documentation 2 within, can say that the disclosed luminous and the present application of patent documentation 2 is completely different.

Also have, in first to six embodiment, by concaveconvex shape, made the phase shifts of light.The movement of phase place also can realize in the mode beyond concaveconvex shape, for example, also can to the thickness of multilayer film and refractive index condition, change in the corresponding region of recess and the corresponding region of protuberance.In this case, certainly also can access the same effect of above-mentioned embodiment.Also think in addition, the first to eight embodiment is not independently just to set up separately, but a part is separately combined as new embodiment.In addition, in the first to eight embodiment, be to take the explanation that organic electroluminescent device carries out as example, but so long as in the large medium of refractive index ratio 1 luminous element just can be suitable for completely.Such as also can be to application such as LED and light guide plate.In addition, the medium of light-emitting device emergent light is not defined as air.The surface structure of above-mentioned embodiment, the refractive index ratio that can be useful in transparency carrier contacts large situation, especially large more than 0.1 situation of refractive index of the medium of transparency carrier.

Utilizability in industry

As above explanation, light-emitting device of the present invention, except making light ejection efficiency significantly improves, the field angle characteristic of emergent light is also good, therefore also useful as display and light source etc.

The explanation of symbol

1 substrate

2 electrodes

3 luminescent layers

4 transparency electrodes

5 transparency carriers

6 air

307 hollow bulbs

308 bonding agents

309 housing departments

In 310a actual effect, refractive index is n _amicrobody A

In 310b actual effect, refractive index is n _bmicrobody B

13 surface structures

S luminous point

Claims (13)

1. a thin slice, by making the face of a side and the transparent thin slice that luminophor adjacency is used, wherein, it is a plurality of tiny area δ below the above 8.0 μ m of 0.2 μ m that the face of the opposite side of described thin slice is divided into inscribe greatest circle diameter, and each tiny area δ by other two above the adjacency in described a plurality of tiny area δ and around

Described a plurality of tiny area δ is by a plurality of tiny area δ that select at random with more than 40% ratio below 98% from described a plurality of tiny area δ _ba plurality of tiny area δ in addition _aform,

At described tiny area δ _ain, disposing thickness is that d and effective refractive index are n _athe first microbody,

At described tiny area δ _bin, disposing thickness is that d and effective refractive index are than n _alarge n _bthe second microbody.

2. thin slice according to claim 1, wherein,

The light wavelength λ that described luminophor sends, described thickness d, described effective refractive index n _aand n _b, meet following relation: λ/6 (n _b-n _a) < d < λ/(n _b-n _a).

3. thin slice according to claim 2, wherein,

Described the first microbody comprises: the mutually different internal structure of refractive index and external structure, and this external structure is surrounded described internal structure, the effective refractive index n of described the first microbody _adescribed refractive index and volume ratio based on described internal structure and described external structure are determined.

4. thin slice according to claim 3, wherein,

Described internal structure is cavity.

5. thin slice according to claim 4, wherein,

Described the first microbody comprises: hollow-particle, and it has as described in-built hollow bulb with as the housing department of described external structure; Bonding agent, it has and the refractive index of the described housing department of described hollow-particle refractive index about equally, and covers described hollow-particle around,

Described the second microbody comprises solid particle and bonding agent, and this bonding agent has with refractive index about equally of the refractive index of described solid particle and covers described solid particle around.

6. a light-emitting device, its there is luminophor and in the light-emitting area of described luminophor set transparent protective seam, wherein,

The face of described protective seam and face opposition side described light-emitting area adjacency; being divided into inscribe greatest circle diameter is a plurality of tiny area δ below the above 8.0 μ m of 0.2 μ m; and each tiny area δ by other two above the adjacency in described a plurality of tiny area δ and around

Described a plurality of tiny area δ is by a plurality of tiny area δ that select at random with more than 40% ratio below 98% from described a plurality of tiny area δ _ba plurality of tiny area δ in addition _aform,

At described tiny area δ _ain, disposing thickness is that d and effective refractive index are n _athe first microbody,

At described tiny area δ _bin, disposing thickness is that d and effective refractive index are than n _alarge n _bthe second microbody.

7. light-emitting device according to claim 6, wherein,

The light wavelength λ that described luminophor sends, described thickness d, described effective refractive index n _aand n _b, meet following relation: λ/6 (n _b-n _a) < d < λ/(n _b-n _a).

8. light-emitting device according to claim 6, wherein,

Described the first microbody comprises: the mutually different internal structure of refractive index and external structure, and this external structure is surrounded described internal structure, the effective refractive index n of described the first microbody _adescribed refractive index and volume ratio based on described internal structure and described external structure are determined.

9. light-emitting device according to claim 8, wherein,

Described internal structure is cavity.

10. light-emitting device according to claim 9, wherein,

Described the first microbody comprises: hollow-particle, and it has as described in-built hollow bulb with as the housing department of described external structure; Bonding agent, it has and the refractive index of the described housing department of described hollow-particle refractive index about equally, and covers described hollow-particle around,

Described the second microbody comprises: solid particle and bonding agent, this bonding agent has with refractive index about equally of the refractive index of described solid particle and covers described solid particle around.

11. thin slices according to claim 1, wherein,

Described inscribe greatest circle diameter is below the above 1.5 μ m of 0.2 μ m.

12. light-emitting devices according to claim 6, wherein,

Described inscribe greatest circle diameter is below the above 1.5 μ m of 0.2 μ m.

13. according to the light-emitting device described in claim 6～10 any one, wherein,

The medium that described protective seam contacts at the face of described opposition side is the little transparent material of protective seam described in refractive index ratio.